Hsu Leonardo Hsu – författare

This book shows how one can combine Yang-Mills gauge symmetry and effective Einstein-Grossmann metric tensors to tackle physical problems at microscopic, macroscopic and super-macroscopic length scales. In particular, the combination of gauge symmetry and an effective metric tensor provides a framework for and leads to an alternative dynamics of cosmic expansion based on quantum Yang-Mills gravity at the super-macroscopic limit. Together with the cosmological principle, one can investigate and derive expanding scale factors, the age of the universe, the cosmic redshift, and the Hubble recession velocity. Furthermore, this framework leads to a possible explanation for the late-time accelerated cosmic expansion due to baryon masses and charges. All these discussions are based on the operationally defined space and time coordinates of inertial frames. Finally, this book expounds on the intimate relationship between space-time translation gauge symmetry and the beautiful ideas of the Lie derivative and Pauli''s variation. One interesting application of the Lie derivative is to formulate a gravitational theory with an external space-time gauge group, which leads to Yang-Mills gravity.

Yang-Mills gravity is a new theory, consistent with experiments, that brings gravity back to the arena of gauge field theory and quantum mechanics in flat space-time. It provides solutions to long-standing difficulties in physics, such as the incompatibility between Einstein''s principle of general coordinate invariance and modern schemes for a quantum mechanical description of nature, and Noether''s ‘Theorem II’ which showed that the principle of general coordinate invariance in general relativity leads to the failure of the law of conservation of energy. Yang-Mills gravity in flat space-time appears to be more physically coherent than conventional gravity in curved space-time. The problems of quantization of the gravitational field, the operational meaning of space-time coordinates and momenta, and the conservation of energy-momentum are all resolved in Yang-Mills gravity.The aim of this book is to provide a treatment of quantum Yang-Mills gravity, with an emphasis on the ideas and evidence that the gravitational field is the manifestation of space-time translational symmetry in flat space-time, and that there exists a fundamental space-time symmetry framework that can encompass all of physics, including gravity, for all inertial and non-inertial frames of reference.

A Broader View of Relativity shows that there is still new life in old physics. The book examines the historical context and theoretical underpinnings of Einstein''s theory of special relativity and describes Broad Relativity, a generalized theory of coordinate transformations between inertial reference frames that includes Einstein''s special relativity as a special case. It shows how the principle of relativity is compatible with multiple concepts of physical time and how these different procedures for clock synchronization can be useful for thinking about different physical problems, including many-body systems and the development of a Lorentz-invariant thermodynamics. Broad relativity also provides new answers to old questions such as the necessity of postulating the constancy of the speed of light and the viability of Reichenbach''s general concept of time. The book also draws on the idea of limiting-four-dimensional symmetry to describe coordinate transformations and the physics of particles and fields in non-inertial frames, particularly those with constant linear accelerations. This new edition expands the discussion on the role that human conventions and unit systems have played in the historical development of relativity theories and includes new results on the implications of broad relativity for clarifying the status of constants that are truly fundamental and inherent properties of our universe.

Prof T-Y Wu is not only an eminent physicist with an encyclopedic knowledge, but also a motivational teacher and an influential policy maker in science and technology. The young Wu was inspired by Prof Y-T Yao, whose course on modern physics sparked an interest that burned during a long and productive career. Among Wu''s achievements are 14 books and more than 120 papers covering subjects from atomic and molecular physics to plasmas and gases to atmospheric physics to relativity theory. Even at the age of 90 he remains active, publishing papers and lecturing on physics.Prof Wu feels grateful that he had the opportunity to educate a group of extremely talented students and, in particular, to discover T D Lee''s remarkable talent. Although creative talent is no doubt a product of nature, it must also be nurtured. Prof Wu has played a crucial role for an entire generation of physicists in China and has won great respect from former students such as C N Yang, T D Lee, K Huang, and countless others. Prof Wu''s love of physics and his dedication in teaching and research will always be remembered.